1. Field of the Invention
The present invention relates to a method for generating three-dimensional video content particularly to a method that is capable of receiving a two-dimensional image signal and directing the two-dimensional image signal to undergo a proper calculation algorithm to therefore transform the two-dimensional image signal into a three-dimensional image signal.
2. Description of Related Art
Growing popularity for 3D motion capture filming techniques has set an inspiring tone for the global community. Added interest to this hotly discussed topic for scientific research about conversion from a two-dimensional image to three-dimensional image was sparkled by the release of the 3D film Avatar directed by the legendary film director James Cameron. A great deal of efforts has been invested to pursue and develop a more advanced image conversion technique aiming for converting two-dimensionality to three-dimensionality in image processing. As well known to persons of ordinary skill in the relevant art, the two main and commonly adapted 3D imaging technique may be categorized into two methods: one being a array-based filming technique, the other being a depth-based filming technique.
It is known that array-based filming technique involves setting a number of video cameras in an array arrangement, where its general practice involves using two video cameras. However, these two video cameras should undergo a corrective process before filming starts so as to ensure that there is no horizontal position displacement issue between these two video cameras. Furthermore the distance between these two video cameras should emulate the distance between a normal person's eyes (i.e. the visual parallax of the eyes), so as to simulate a possible perspective of a normal person. In another aspect, the requirement for these two video cameras to be maintained in a synchronous state at a run-time setting incurs extraneous effort and time during use of the equipments. In another aspect, these two video cameras may be subject to changes in light abundance or changes in internal parameters of the video cameras, making the three-dimensional images so captured open to discoloring.
It is also known that depth-based filming technique turns to use one traditional video camera while also coupling with another depth video camera for filming purposes. Generally speaking, the aforementioned depth video camera operates on a “time of flight” principle, working by means of calculating the time period from the emitted infrared light hitting the desired object to the same infrared light returning back into the depth video camera, so as to determine the actual distance between the desired object for phototaking and the video camera. In addition, the relative distance between the aforementioned traditional video camera and the aforementioned depth video camera may be subject to adjustment prior to filming begins so as to ensure that the pixels picked up by the traditional video camera are all well aligned with their corresponding depth value. Unfortunately, the depth resolution offered by the depth video camera still faces serious limitation, and it is not possible to provide a depth image of high image resolution, which altogether creates room for improving the image quality of composite three-dimensional image.
Inasmuch the aforementioned two techniques may already be capable of forming three-dimensional image content, the underlying issue of increased operating cost with these setups remain to be of concern as, for example, the array-based filming technique requires a multiple number of video cameras to be on standby during filming. Taking into another consideration, another disadvantage hereof is that the three-dimensional image produced therefrom will be more open to distortion and become useless if each participating video camera is not adjusted relative to its position from one another or does not synchronize accordingly. Another disadvantage associated with the known setups is of the high price for a depth video camera, which has demonstrated to be a barrier for higher market penetration, making it less possible to effectively lower operating cost for producing a three-dimensional video content with a depth video camera.
Owning to the disadvantage of high filming cost arising from three-dimensional image capturing, effective approach for maintaining quality image while keeping the rate low on producing three-dimensional images has been a popular issue for further research in the industry and academia. Also, two-dimensional image signal is the type of image signal that is most commonly used in the current relevant state of art. It will therefore be understood that the issues encountered by the aforementioned ways for obtaining three-dimensional image content (three-dimensional image signal) will be overcome if a new way for converting two-dimensionality into three-dimensionality is found.
Accordingly, there is a demand in the industrial sectors for a method for receiving a two-dimensional image signal and directing the two-dimensional image signal to undergo a proper calculation algorithm to therefore transform the two-dimensional image signal into a three-dimensional image signal.